Gas compressor



July 4, 195o G. P, cusmNG 2,514,224

GAS COMPRESSOR Filed March 10, 1947 IN VEN TOR. efoer P (usm/v6.

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Patented July 4, 1950 UNIT EDL- SL-T'ATES 0F F ICE Ges COMPRESSOR Gregory P. Cushing, Chicago, Ill; Application lllarclrA 10, 1947,'.Serial No.'133,467

This invention` relates to improvements in gas compressors, and more particularly tu a gas compressor of the rotary,A non-reciprocating type, or to a vacuum pump.

The primary object ofthe invention is to pro- 12' Claims; (Cl. 230A-108)- vide a novel. simple, inexpensive and' efficient gas compressor operating by the centrifugal action oil arotor uponl small bodies of a liquid fedthereto intermittently which serve to draw and'. trap gas in areceiver. under pressure.

A` further object isr to provide a device of" this character` adapted to` rotate at high speed, which isl inherently and automatically balanced stati'.- cally and dynamically under'allV operating, conditions.

A, further object, is to provide a deviceof this l for measuring the liquid is located; centrally in the centrifugal device so that it travels .at low pe'- ripheral' speed compared tothe peripheral speed of the discharge portion of` the device, thereby preventing` excessive fluid turbulence in the operation of the, device.

A further object is to provide agas compressor ofthe. type in` which gas is pumped by. the action of liquid` movingy under centrifugal'force', wherein the separation of the gas. from the liquid is accomplished under dynamic conditions, with minimumseparationlosses.

Aiurther object is to provide a device oft this character, wherein gas under pressure. pumped in the operation oi the device ows in a counter een.- trifugal direction from the. gas-liquid separation portion of. the device to insure. dehumdification of the gas.

A further object. of` the, invention is` to provide a. gas compressor using liquid under centrifugal force as thepressure generating, medium, where,- inthe liquid is trappedat a gas separation` point from which it is. discharged to. a liquid. outlet. in a gradual ovv under low. pressure and with in.- herent kinetic energy actingupon the liquid to facilitate recirculationthereoi.

Other objects will be apparentfromthe. following specication.

Inthe drawing:

Fig. 1 is a transverse sectional view taken on line l--l of Fig. 2.

Fig. 2 is anaxial sectional view of the device taken on line 2-2of Fig, 1.

Referring to the drawingl which illustrates the preferred embodiment of the invention, the' nue- 2 meral l0 designates. a substantially flat end wall of a; casing; which Wall is provided with a cen.- tral circular aperture H therein. The end Wall li) ispreferably of the shape bestillustratedby the `overall outline of the form of the. device shown in Fig. 1j. A flangev i'2iextends perpendicularly from the plate Ui'at/ its margin. andvdeilnes the outer wall of'the casing. The casing has(y a rear wall i3 having a; central aperture r4. The wall I3 forms the base of a cup-shaped: casing part having; an integral annular forwardlyV project-,ing` flange or wall. portion l5 formed;v atv its marginv and terminating in a. planar or flatk out.- Wardlyprojecting flange I 6i whose outerv marginis of the-same. shape or contour as'the ange I2 of the front' wallv of the casing and; which is preferablyI securedA at the edgel of Said flange I2 by securing-members I1 which rigidly connect" the casing lparts together. The joint between the flanges I2 and I6 isv sealed'in any suitable man-y ner as by the provision of sealing gaskets between tlie casingfp-artslo A pair of spaced coaxial bearings 2liand 21 are, mounted' in any suitable manner in fixed relation' to thecasing and the bearing 2 lv journals a. sleeve 22` from whose inner end projects' an enlarged-'portion 23 havinga peripheralA groove 24;` whereby the part 23 constitutes a pulley for a. V" belty (not shown); The pulley portion 23 is'of a diameter slightlyI lessA than the diameter of the' aperture i4; in the wall I3 of' the casing, whereby the pulley 23'may extend freely into the casing; A rotor 25 is'xedly mountedv upon the inner` end of* thev pulley 23` within thecasing ad'- jacent to the Wall I3 thereof and preferably par'- allel to, the wall i3. The rotor 25 is of cupshaped form and' has a marginal flange 26 formed integrally therewith at its 'periphery and terminating in an annular lip portion 21 positioned adjacent to but spaced rearwardly from the wall l0' of the casing; The rotor parts 25, 26., 2T are allspaced free andA clear of the casing parts, Wherebythey are free to rotatewithin the casing without frictional; contact therewith.

A'tube 28'is. iixed within the. sleeve 22 at one of.' itsv ends .and projects. therefrom through.' the casing to, terminatey in aj 'ared mouth portion 29 spaced outwardly from the casing wall l0. The tube 28j xedl'y mountsa hub 30j which is; jour.- naled in the bearing 20 and which extends freely through the aperture ll in the plate l0. A second rotor 3l inthe nature of a disk is carried by the inner end. of the hub 30v substantially centrally between and spaced.' from the inner face ofthe rotor 2,5 and the plane ofthe. outeror fore ward surface of the annular iiange 21 of the rst rotor. The second rotor 3i has a plurality of equiangularly related radial bores 32 formed therein. The rotor has a circumferential groove 33 formed in the face thereof confronting the rotor 25 in spaced relation to its margin, and the outer ends of the bores 32 open at said groove 33. The inner ends of the bores 32 are open at the inner periphery of the rotor and each communicates with the interior of the tube 28 by means of a registering aperture 34 formed in the tube 28 duced thickness and is rearwardly offset from the face of the rotor 3l which confronts casing wall l0, thereby providing an offset 35 therein at the periphery of the rotor which permits the marginal flange 35 to be positioned substantially centrally between the rotor 25 and its annular ange 21, as best seen in Fig. 2.

The tube 28 has a plurality of openings 35 formed therein in longitudinally spaced relation to the ports or openings 34 and communicating with the space between the rotors 25 and 3l. An outlet tube 31 projects into the tube 28 and terminates short of the openings 36 of said tube. The' tube 31 is preferably stationary and is journaled within the tube 28 and leads to any suitable gas discharge outlet.`

A partition 38 extends transversely across the tube 28 between the two series of openings 34 and 36 to bar passage of fluid through said tube 28. vThe member 36 is iixedly secured to the tube be a speed suiiicent to produce centrifugal action. The lines 42, 4G of the liquid recirculating system may be connected with a reservoir of liquid (not shown) if desired, or the system may otherwise have a supply of liquid interposed therein. For the purposes of this invention any liquid may be used, although water is preferred in most instances. The water is supplied through the inlet pipe 42 at low pressure and discharges therefrom at the cut-out portion thereof defined by the end 43 of the tube, for passage by centrifugal force through those ports 4I of the sleeve 39 which register with the cut-out or cut-outs of the tube 42. The projection or projections 44 are so arranged and are of such circumferential size that when the device is operating at a predetermined speed dependent upon the pressure desired to be generated, the now of liquid to each in Fig. 2. At the time that the projection or :28 to rotate therewith and has xedly secured i concentrically therewith a tube 39 ofv smaller diameter than tube 28 and projecting toward the inlet end of said tube as illustrated in Fig. 2. The portion 40 of the tube 39 is of increased thickness and outer diameter and has a plurality of equispaced passages 4l extending radially therethrough, each in axial alignment with one of the radial bores 32 of the rotor 3i. A liquid intake pipe 42 connected with a fluid circulating system projects into the sleeve 39 which is freely rotatable therearound. The tube 42 terminates at 43 in outwardly spaced relation to openings 4| in the member 40 for the major portion of its extent, but at one or more portions 44 thereof the tube 42 extends substantially into engagement with the partition 38, said portion or portions 44 each being of a circumferential dimension adapted to close off a selected number of thekports 4l. The liquid circulating system, of which the pipe 42 constitutes the outlet, is preferably connected at an outlet portion 45 of the vconvoluted casing wall i2 by the inlet conduit 48 shown in Fig. 1.

In the operation of the device, a belt is trained around the pulley 23, 24 and is driven at desired speed for the purpose of rotating the pulley and its associated parts. It will be understood, however, that while provision for a belt drive has been shown herein for purposes oficonvenience, ,a gear drive or any other desired type of drive may bev used instead of the belt drive. Rotation of the pulley '23 is transmitted to the rotor, 25, 25, 21carried by the pulley 23 and is alsotransmitted through the rotation of the tube 28 to `the rotor 3l and the sleeve 39. The arrangement is such that rotation of the rotor 25, therotor i3! and the sleeve 39 is the same; that is, that these parts operate at the same number of revoluftions per minute. The speed at which the parts rotate may be any speed selected, depending upon projections 44 of the tube span any selected port 4| in the sleeve 39, gas, such as air, which is introduced through the leithand end of the tube 28, is free to pass throughthe port 34 into the aligned bore 32 of the rotor. The globules oi liquid 41 travel outwardly into and through the bores 32 ofthe rotor by virtue of centrifugal action and create theiebehind in each of the bores a suctionfefe'ct which serves to drawthe gas therein. Thus during each revolution of the rotors, aA charge of gas will be drawn into the inner end of each bore 32 by the suction action of the movngglobule 41. In this connection it will be understood that, if two projections or cut-ons 44 areprovided, then there will be two charges of gas introduced inv each revolution of the rotor. Thecut-oiis 44 should be so correlated with the rotor that ,at least one globule 41 of liquid is contained in each'rotor bore 32 at all times. This prevents gas discharge through the bores 32 counter-centrifugahy Where the device is used for the purpose of compressing air, the lefthand 'end ofthe tube 28 is open to atmosphere for free entry of air into the tube as illustrated. In cases where other gasesv are to be compressed, the compressor may be positioned within thelow pressure gas container, or a suitable reservoir (not shown) for the gas may be iixedly associated with the housing of the compressor surrounding" tube 28, the pipe 42 passing therethrough with a sealed fit, as will be obvious'to those skilled in the art.

The liquid globules 41 which are forced through the bores 32 by centrifugal action are discharged at the mouths of the'bores opening at the groove 33 in the rotor. Note in. Fig. 2 that the radius of the outermost portion of the groove 33 is substantially equal'to the inner radius of the annulus 21 of the rotor 25. Consequently, in the operation of the device, the continued radial vdischarge ofthe watergl'obuleslll forms a body of liquid 48 at the margin ,ofl the'rotor 25 which is trapped by the annulus 21, so that the'margin 35 of the rotor 3l is traveling in said body of water 4B. The gas which is withdrawn by suc- 'tion throughthe bores 32 behind each of the globules 4lv is prevented. from passing around the periphery of the rotor 3l by the. liquid seal aiorded. by the positioning of the rotor margin in the trapped liquid 48. Consequently, this air must travel through the passage 49 between the rotors 3l and 25 in a counter-centrifugal movementl for dischargev through the .ports 36 into the outlet tubev 3l. In other Words, the body of liquid 48 at the margin of the rotor 2.5 forrnsa liquid` seal for the entrapped air,which seal is efective as long as the rotors continue to operate at a speed suiiicient to exert centrifugal actionA upon the liquid in the device. As water is continually added to the body 48 at the margin of the rotors incident to operation of thev device, it is bled oi or spillsover; the lip of the annulus 2l into the convoluted passage 50 whose shape is determined by the outer wall I2 of the casing part ill. This water has a.l certain kinetic energy due, to the; operation of the rotor and travels to the outlet. of the convoluted passage for discharge Ainto the conduit 46 under low pressure to provide for recirculation thereof to the inlet conduit 42 associated with the conduit 46 in the liquid recirculatingl system.

It will be apparent that if the air or other gas which is drawn through the device and compressed thereby has any moisture content, due either to its humidity or to the presence of the liquid globulesl 4l, that moisture content is removed in the operatio-n of the. compressor. The moisture content of the gas is subject to the centrifugal action whichV causes it to .be discharged into and become apart of the liquid 48 trapped in the rotor. Thus, in addition to the pumping of the air or other gas in the operation of the device, there is an eicient dehumidication of the gas under dynamic conditions which is characterized by minimum separation losses.. I n other words, the moisture content of the gas is discharged centrifugally, whereas the gas itself is sealed against centrifugal discharge in the event it is subject thereto, and a pressure is built up inthe chamber 49 whose only outlet is ina `counter-centrifugal directionl through the openings 35 inthe device.

Another factor of importance in. the operation of the device is that the projections or cut-offs 44 and the ports 4I of the device` which govern the formatiouand the size of the liquid globules 4l are positioned centrally of the device, whereby said ports 4| rotate -relatively to the cut-offs 44 at low peripheral or linear speed compared to the peripheral or linear speed of the other rotating parts of the device. This results in a smooth globule-forming action with minimum tendency to create turbulence of either the liquid or the air through which the globule passes for entry through the port 34 into the aligned bore 32 of the rotor.

Still another feature of the device which is of considerable importance is that,v assuming that the construction of the device is such that the rotating unit of the device is inherently balanced both statically and dynamically, that balance is not disturbed during the operation of the device. This is accomplished by virtue oi the fact that each of the bores 32 has some Water therein at all times by virtue of the fact that the cut-offs '.tates. high speed operation vof the compressor and reduces thelikelihood oivibraton and chatter or other conditions which would tend to produce undesirable wear of the parts of the device.

While the device has been illustrated herein with the hub 3U fitting freely and withv clearance in the casing opening l I, and with the pulley 23 similarly freely fitting in the casing opening i4, it will be obvious that suitable journals or bearings may be provided at these points.

While only one form of the compressor has been illustrated and described herein, it will be understood that changes may be made therein within the scope of the appended claims Without departing from the spirit of the invention.

I claim:

l. A gas compressor comprising a, casinghaving a peripheral liquid outlet port, a tube extending axially through said casing and rotatable relative; thereto, a pair of rotors fixed on said tube within said casing, one of said rotors being cup-shaped and having an inwardly projecting annular flange at its margin, the other rotor iitting within and spaced from said cup-shaped rotor and being of a diameter greater than the inner diameter of said flange,- said second rotor having a plurality of equispaced bores open at their inner ends at its center and at their outer endsl at the side of the rotor inwardly spaced from its periphery and confronting said rst rotor, said tube communicating with a supply of gas and having a set of openings communicating with the inner ends of said bores', means positioned centrally of said rotor for successively injecting measured quantities of a liquid into said bores during rotation of said rotor, said tube having a second set of openings for exhaust of gas discharged into the space between said rotors, a barrier in said tube between said two sets of openings, and means for collecting gas dism charged into said tube through said second set of tube openings.

2. A gas compressor comprising a casing having a peripheral liquid outlet port, a pair of spaced concentric rotors in said casing each having a hollow hub projecting from said casing, one rotor having a plurality of equispaced bores each open at its inner end at said hub and open at its outer end at the side face confronting the other rotor in spaced relation to the rotor periphery, means located in the hub of said rotor for successively introducing measured quantities of liquid into said bores during rotation of said rotor, the other rotor having a peripheral iiange tting freely around said first rotor and terminating in an annular flange whose inner edge is spaced outwardly from the outer ends of said bores and inwardly from the periphery of said first rotor, the hub of the rst rotor communicating with source of gas, means projecting into the hub of the second rotor for collecting gas discharged into the space between said rotors, and means for rotating said rotors.

3. A gas compressor comprising a casing having a peripheral liquid outlet port, a pair of spaced concentric rotors in said casing each having a hollow hub projecting from said casing, the hub of one rotor communicating with a source of gas, said rotor having a plurality of substantially radial bores each open at said hub and discharging inwardly of its periphery at the face of said rotor confronting the other rotor,v the other rotor having a rim spaced from and dening an annular channel tting around the marginal portion of said lrsll rotor outwardly of the discharge ends of said bores, a gas receiver communicating with the hub of the. last named. rotonmeans in the hub of said rst rotor for successively feeding measured quantities of liquid into said rotor bores, and means for rotating said rotors, said rim channel serving to centrifugally trap a body of liquid into which margin of the bored rotor projects to form a gas retaining seal.

4. A gas compressor comprising a casing having a peripheral liquid outlet, an impeller in said casing having a hollow hub projecting from said casing and communicating with a source of gas, said impeller including a disc having passages each open at said 'hub and at one face thereof spaced inwardly from its periphery, means in said hub for intermittently feeding measured quantities of liquid into each passage, a cupshaped retainer in said casing having a hollow hub projecting from said casing an-d communieating with a gas receiver, said retainer confronting the outlets of said passages and having an inwardly bent marginal portion extending around and spaced from the marginal portion of said disc and terminating outwardly of the outer ends of said passages, and means for rotating said impeller and said retainer.

5. A gas compressor comprising a casing having a peripheral liquid outlet, an impeller disc rotatable in said casing and having a tubular hub projecting from said casing and communicating with a source of gas, said impeller having a plurality of substantially radial passages open at said tubular hub and having their outlets at a side face of said disc spaced inwardly from its periphery, a rotor concentric with and confronting the outlets of said impeller and having an annular marginal channel opening inwardly and receiving with clearance the marginal portions of said impeller located outwardly of the outlets of said passages, said rotor having a tubular gas-receiving hub projecting from said casing, means for periodically feeding to each impeller-passage a small quantity of liquid, and means for rotating said impeller and rotor.

6. A gas compressor comprising a casing having a peripheral liquid outlet, an impeller disc rotatable in said casing and having a tubular` hub projecting from said casing and communicating with a source of gas, said impeller having a plurality of substantially radial passages open at said tubular hub and having their outlets at a side face of said disc spaced inwardly from its periphery, a rotor concentric with and confronting the outlets of said impeller and having an annular marginal channel opening inwardly and receiving with clearance the marginal portion of said impeller spaced outwardly from said passage outlets, said rotor having a tubular gas-receiving hub projecting from said casing, means for periodically feeding to each impeller passage a small quantity of liquid, said impeller and rotor being xedly secured together as a unit, and means for rotating said unit.

7. A gas compressor comprising a casing having a peripheral liquid outlet, an impeller disc rotatable in said casing and having a tubular hub projecting from said casing and communicating with a source of gas, said impeller having a plurality of substantially radial passages open at said tubular hub and having their outlets at a side face of said disc spaced inwardly from its pelriphery, a rotor concentric with and confronting the outlets of said impeller and having an annular marginal channel opening inwardly and receiving with clearance the marginal portion of 'said impeller radially outwardly spaced from said Ioutlets, said rotor having atubular gas-receiving hub projecting from said casing, means for periodically feeding to each impeller passage a small quantity of liquid, said impeller and rotor being xedly secured together as a unit, and a drive pulley carried by one of said projecting tubular hubs.

8. A gas compressor comprising a casing having a peripheral liquid outlet, an impeller disc rotatable in said casing and having a tubular hub projecting from said casing and communicating with a source of gas, said impeller having a plurality of substantially radial passages open at said tubular hub and having their outlets at a side face of said disc spaced inwardly from its periphery, a rotor concentric with and confronting the outlets of said impeller and having an annular marginal channel opening inwardly and receiving with clearance the marginal portion Aof said impeller, said rotor having a tubular gasreceiving hub projecting from said casing, means for periodically feeding to each impeller passage a small quantity of liquid, and means for rotating said impeller and rotor, said liquid feeding means including a sleeve secured concentrically within said impeller hub and rotatable therewith, said sleeve having a plurality of apertures each substantially aligned with one of said impeller passages, and a stationary liquid conduit fitting snugly within said sleeve and having a lateral outlet of limited circumferential extent communicating with at least one of said sleeve apertures at all times.

9. A gas compressor comprising a casing having a peripheral liquid outlet, an impeller disc rotatable in said casing and having a tubular hub projecting from said casing and communieating with a source of gas, said impeller having a plurality of substantially radial passages open at said tubular hub and having their outlets at a side face of said disc spaced inwardly from its periphery, a rotor concentric with and confronting the outlets of said impeller and having an annular marginal channel opening inwardly and receiving with clearance the marginal portion of said impeller, said rotor having a tubular gas-receiving hub projecting from said casing, means for periodically feeding to each impeller passage a small quantity of liquid, and means for rotating said impeller and rotor, said liquid feeding means including a sleeve carried by and positioned concentrically within said impeller hub to define an annular space therearound and having a circumferential series of apertures each aligned with one of said impeller passages, a stationary liquid supply conduit projecting into said sleeve. and a cut-ofi member carried by said conduit and positioned to span and close a selected number of said sleeve apertures.

10. A gas compressor comprising a casing having a peripheral liquid outlet; a rotor in said casing, said rotor having spaced axial gas inlet and outlet passages, a plurality of radial impeller passages communicating with said inlet, and a radial transfer passage communicating with said outlet passage, said impeller passages communicating with said transfer passage at a point spaced inwardly from the outer part of said transfer passage, said transfer passage being open at one side of the peripheral portion of said rotor and return bent at its outer portion and radially outwardly of the points of communication of said impeller passages therewith; means for driving said rotor; and means in said inlet for successively feeding measured quantities of liquid intosaid impeller passages.

11. A gas compressor comprising a casing having a peripheral liquid outlet; a rotor in said casing, said rotor having spaced axial gas inlet and outlet passages, a plurality of radial impeller passages communicating with said inlet, and a radial transfer passage communicating with said outlet passage, said impeller passages communieating with a radially intermediate portion of said transfer passage, said transfer passage being open at the peripheral portion of said rotor and said rotor including a bent annular marginal lip spaced radially outwardly relative to the points at which said impeller passages communicate with said transfer passage and defining a liquid trap in said transfer passage; means for injecting measured quantities of liquid at the inner ends of said impeller passages; and means for driving said rotor.

12. A gas compressor comprising a casing having a peripheral liquid outlet; a rotor in said casing, said rotor having a plurality of passages therein including axial gas inlet and outlet passages, radial impeller passages communicating with said gas inlet and a transverse transfer passage communicating With said outlet and open at the peripheral portion of said rotor, said impeller passages communicating With radially intermediate portions of said transfer passage; means carried by said rotor dening a liquid trap in said transfer passage located radially outwardly of the points of communication of said impeller passages with said transfer passage, means for introducin measured quantities of liquid in said impeller passages successively; and means for driving said rotor.

GREGORY P. CUSHING.

REFERENCES CITED The" following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,457,536 Maclean June 5,1923 1,689,439 Lawaczeck Oct. 30, 1928 2,035,786 Bradley Mar. 31, 1936 

